<html>
<head>
  <style type="text/css">
    legend{font-weight: bold;}
    fieldset{background-color: #fdf5e6;width: 50%;}
  </style>
  <script type="text/javascript">
    function el(elementId) {
      return document.getElementById(elementId);
    }
    function concat() {
      el('result').value = (el('v1').value + el('v2').value);
    }
  </script>
</head>
<body>
<fieldset>
  <legend>Concatenator</legend>
Value1: <input id="v1" type="text"/><br/>
Value2: <input id="v2" type="text"/><br/>
<input id="concat" type="button" value="Concatenate" onclick="concat()"/><br/>
Result: <input id="result" type="text" disabled="disabled" /><br/>
</fieldset>
</body>
</html>